Kim Prunster found guilty of attacking partner with kitchen knife in Dongara

On the last morning she was to spend with her childhood sweetheart before moving out, Amanda Gibbons woke to find him kneeling next to the bed, centimetres from her face, staring.

Key points:

Kim Prunster was found guilty of grievous bodily harm to his partner of 34 years

Prunster stabbed Amanda Gibbons up to 15 times with a serrated kitchen knife

He was remanded in custody and is due to be sentenced on June 4

His eyes were "black, vacant, like not focused" Ms Gibbons told a WA Supreme Court jury.

She felt a blow to her chest, then her stomach.

"Then I realised he was stabbing me," Ms Gibbons said.

He stabbed her up to 15 times.

Today 57-year-old Kim Ashley Prunster was found guilty of causing grievous bodily harm with intent, but was found not guilty of the most serious charge of attempted murder of his partner of 34 years.

A Supreme Court jury in the WA town of Geraldton heard Prunster attacked the mother-of-four with a serrated kitchen knife in the bedroom of their home in the coastal town of Dongara, 350 kilometres north of Perth.

Ms Gibbons, 52, gave evidence via video link about the attack on November 12, 2017, which left her with abdominal injuries and a collapsed lung.

"I heard a hiss then felt the blood pumping out," Ms Gibbons said.

"As I rolled away I got one in my arm. I don't know how many times he stabbed me in the back."

She told the court she walked, bleeding, to her adult son's bedroom and a neighbour took her to the local medical centre.

That night they listened to music while drinking beers in their carport.

On Saturday night Prunster said he asked Ms Gibbons for a hug and she questioned why because "it wouldn't mean anything".

The attack happened early on Sunday morning.

Willed act or dissociative state

"If his mind went into that dissociative state … then his actions were involuntary and not a willed act," Mr McKenzie argued.

The defence called forensic psychiatrist Gosia Wojnarowska who said, based on an interview with Prunster and hearing the evidence, it was "highly likely that he did" suffer dissociation.

She said dissociation was a "protective mechanism" following trauma.

"A person who dissociates would present as vague, their facial expression changes and they don't make eye contact," Dr Wojnarowska said.

But she acknowledged people could feign symptoms and psychiatrists had to believe what they were being told.

The prosecution called upon psychiatrist Adam Brett, who testified Prunster's "purposeful" actions of going to the kitchen, getting a knife and returning to the bedroom to stab his partner were incompatible with being in a dissociative state and it was "very unlikely" he was in such a state.

He said there was "no question [Prunster] was devastated" and had physical symptoms several days before the attack that were consistent with a "panic like" stress reaction.

"I think it did exceed his level of resilience, but that doesn't mean he went into a dissociative state," Dr Brett said.

Prunster was remanded in custody for sentencing on June 4, with the judge requesting a psychiatric report.